Lesson 4

1. Lesson 4 CHEMICAL BASIS OF LIFE: BIOLOGICAL MOLECULES

2. RECAP TIMEBIO FACTS

3. Competencies

4. Activity (10 mins) Guide Questions: 1. What is a protoplasm? 2. Why is it called the chemical basis of life? 3. What are biological molecules? 4. What are their functions?

5. PROTOPLASM • Protos- First, Plasma - form • material basis of life or chemical basis of life • – living substance in which all animals and plants are made. • The word was coined by Hugo Von Mohl • Characteristics: -fluid, viscid, ductile and less transparent • -Aggregate of crystalloids and colloids • -reversible in sol gel system

8. 3 Components: • Elements: • OCHN – 96 %, PSMgCa – 4% • oxygen • – oxidation of glucose • carbon • – component of organic molecule • hydrogen • – influence pH of body fluids • Nitrogen • – component of proteins and nucleic acid

9. 2. Inorganic Compounds – lack carbons • Water • – 75% of the protoplasm, 2/3 of the body weight • Functions: • - neutral solvent • - dispersion medium • - participate in enzymatic rxn. • - Essential for metabolic activities • - Chief excretory product.

10. Properties: • High heat capacity • Polarity or Solvent Properties • Chemical reactivity • Cushioning

11. Salts • – contain CA and Phosphorous • – when dissolved in water separate into ions process is called Dissociation. • Salts are electrolytes • - they can conduct electrical current in solution. • Functions: • maintenance for osmotic pressure • clotting in blood • development of bones and teeth • formation of hemoglobin in rbc • normal functioning of muscles and nerves

12. Acids and Bases – • - are electrolytes, they ionize and then dissociate in water and can conduct electrical current. • ACIDS – sour taste and can dissolve metals • they release hydrogen ionsalso known as proton donors • Bases – have a bitter taste • proton acceptors; hydroxides • are commonly inorganic bases

13. the relative concentration of hydrogen ions in various body fluids is measured in concentration units • -called pH. • - pH scale – 1909 – Danish biochemist – Sorensen – referred based on number of protons in solution expressed in moles per liter. • - 0-6 is basic and 7 -14 is acidic

14. 3. ORGANIC Compounds – - Carbon containing compounds substances derived from organism – known as macromolecules and the essence of life. Types: 1. Carbohydrates – most abundant, sugar and starch contain CHO group – made synthetically from water and carbon dioxide Functions: - source of chemical energy - components of protoplasmic structure

15. Types: • Monosaccharide • – simple sugar • Examples: glucose – blood sugar • Fructose/galactose • – converted to glucose for body • Ribose/deoxyribose • – part of nucleic acid

16. b. Disaccharides – double sugar Examples: Maltose – malt sugar - 2 glucoses Sucrose – table sugar – glucose plus fructose Lactose – Milk sugar – glucose plus galactose

17. C. Polysaccharides – complex sugar – ideal as storage products • Examples: • 1 starch • – plants • 2. glycogen • – animals • cellulose • – cell wall • Chitin • – egg • Agglutinogen • – blood

18. 2.Fats and Lipids – 2-3% of the cell – diverse group of organic compound. Fats – mixture of triglycerides and steroids Lipids – fatty acids and glycerol Functions: - storage form of metabolic fuel - provides heat and energy - important part of cell organelles - important process in denaturation and photophosphorylation

19. Types of fats: a. Neutral Fats or simple lipids – triglycerides - building blocks: fatty acid and glycerol types: a. natural fats – examples – tallow, lard, butter and human fats. B. waxes – bees wax and ear wax

20. b. Phospholipids – phosphorous containing group - found in cell membrane, participate in transport of lipids and insulate the white matter in the brain. Example: Cephalin

21. c. Steroids - Fat molecules formed by 4 interlocking rings • examples: • cholesterol • – basis of all steroids • bile salts • – fat digestion – liver • vit D. • – for normal bone growth – skin • sex hormones • – normal reproductive functions • Adrenal Cortical Hormones • – cortisol – anti stress hormones

22. 3. Proteins – 10-20% of the cell – 50 % of organic body – building block known as - amino acid Functions: - growth of new tissues and repair of old. - maintenance of osmotic pressure - important in formation of enzymes

23. Types: a. Fibrous proteins/ Structural – basic structural materials of the body. Examples: albumin – blood and egg white Globulin – plant seed Histone – nucleic acid Protamine – sperm cells

24. b. Globular Proteins/ functional proteins – play role in biological processes. • Groups: • Antibodies – Immunoglobulins • Hormones – growth hormone and insulin • Transport proteins – hemoglobin • catalyst – enzymes • – functional proteins that hasten chemical rxn without itself involve in the process. • - for biochemical rxn.

25. 4. Nucleic Acids – polymers of nucleotides – made up of genes – blue print of life – largest biological molecules in the body. building blocks of NA - Nucleotides – Functions: participate in molecular mechanism and biosynthetic rxn. Parts: 1. nitrogen containing base 2. 5 carbon sugar – pentose 3. phosphate group bases: adenine, guanine, thymine, cytosine

26. Differences between DNA and RNA: DNA RNA Nucleus nucleus and cytoplasm Pair – a-t, g-c pair – a-u,g-c Dexyribose ribose 2 strand 1 carrier of genetic code for protein synthesis

27. 5. Adenosine TriPhosphate – ATP – energy currency of the cell – provide form of chemical energy – a modified nucleotide

28. Applicationdetermine the classification of organic compound:1. Pentose2. enzymes3. immunoglobulins4. cephalin5. cerumin6. sucrose7. cytosine8. thymine9. guanine10. lard11. growth hormones12. bile salts13. steroids14. maltose15. nucleotides